Clinical and radiographic outcomes of stress-free implant (SFI) bars and Milled bars for early loaded implant supported mandibular overdentures. A one-year randomized trial

Objectives: The aim of the present trial was to compare clinical and radiographic outcomes of stress-free implant(SFI) bars and Milled bars for early loaded implant supported mandibular overdentures.
Materials and methods:Ten completely edentulous participants were selected. Patients were allocated in 2 groups :group 1 include 5 patients who received milled bar overdentures, and group 2 include 5 patients who received SFI bar overdentures. Four implants were inserted according the flapless surgical protocol in canine and frist molar areas and early loaded by milled bar(group 1)or SFI bar(group2) 2weeks after implant placement. Plaque and gingival indeces, pocket depth, fixture stability, and peri-implant bone resorption were measured at base line, 6 and 12months after prostheis delivery.
Results:The survival rate was 95% and 100% for milled bar and SFI bar groups respectively. Plaque index and pocket depth significantly increased with passage of time for milled bar group only and SFI bar showed no difference in these parameters between observation times. Bone loss increased from 6 to 12 months significantly in both groups. No significant difference in gingival index and fixture stability between observation times or between groups were noted. Milled bar group showed significant higher plaque, pocket depth, and bone resorption than SFI bar group after 6and 12months.
Conclusion:Within the limitation of this randomized trial, it could be concluded that SFI bar is more advantageous for early loaded 4 implants supporting mandibular overdentures than milled bar as it was associated with decreased plaque accumulation, pocket depth and marginal bone resorption after one year.